Improvement in hydraulic-pressure accumulators



T. SHAW. Hydraulic Pressure Accumulator.

No. 214,716. Patented April 22,1879.-

[N VENTOR WITNESSES:

ATTORNEY N. E TERS. FHOYOVLITHOGRAPHER. WASHXNGTON. D C.

UNITED STATES PATENT OFFICE.

THOMAS SHAW, OFPHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN HYDRAULIC-PRESSURE ACCUMU-LAT'ORS.-

. Specification forming part of Letters Patent No. 214,716. dated April22, 1871); application filed April 19, 1878.

To all whom it may concern: I

Be it known that I, THOMAS SHAW, of the city and county of Philadelphia,Pennsylvania, have invented a new and Improved Hydraulic-PressureAccumulator; and 1 hereby declare the following to be a full, clear,

and exact description of the same,.reference being had to theaccompanying drawing, and to the letters of reference marked thereon.

My invention consists in the provision of a pressure floating piston inan air-chamber cylinder, and in the inclosing of a light pistoncylinderwithin a powerful hydraulic cylinder, and in the construction ofhydraulic cylinders and operating the same, all for the purposehereinafter described.

The object of the invention is to store up fluid-pressure by thecompression of gases, and to utilize the same without loss of theelastic medium, and to construct the device in a cheap and durablemanner, as hereinafter described.

In order to enable others tome and practice my invention, I will proceedto describe its construction and operation. On reference to theaccompanying drawing, which forms part of this specification, the sketchrepresents avertical section through the center of apparatus, of which--a is a pillar supporting the entire apparatus, and is firmly secured tocylinder b, which is provided with an inlet and outlet aperture, 0, andis firmly secured to cylinder-head d by screws 0. g is a drawn-brass orlight cylinder-tube, provided with a screw-thread at its lower end, toenable a firm attachment to cylinder-head d, and is supported from anylateral motion by screw 5, projecting through the upper cylinder-head,m. The said tube 1 is provided with apertures at the top, opening intothe space formed by cylinder h, and is open at the lower end intochamber 1), and contains a moving piston, n, which piston is providedwith ordinary cup-packing at both ends, and with a central aperturethrough the same, with an ordinary valve in said aperture openingupward, all for the purpose as hereinafter described.

The cylinder h is constructed of a light lapwelded tube, screwed intocylinder-heads d and m, and the longitudinal strain of internal pressureis taken up upon bolts k, and the cross-strain of internal pressure istaken up upon successive coils of wire wound in a uniform and permanentmanner around said tube, the ends of said wire being secured in a firmmanner, all for the purpose as hereinafter described.

f is a small tube that leads to the bottom of chamber h, for the purposeof drawing ofi' fluid from said chamber through cock I, for the purposehereinafter explained.

The device is operated in this wise: Air or other gas is forced intochamber h through cock I, or other convenient inlet, until a pressure ofair shall have accumulated in said chamber equal to the minimum ordesired hydraulic pressur e The pressure of ainwithin chamber h, havingaccess'to theinterior of tube 9 through the aperture in the top of saidtube, presses heavy upon piston 12, and forces down upon the supportingend of pillar c, which projects up through chamber 0. The slender tube 9is not injured by any pressure applied in this manner, by reason of thepressure being the same on both sides, rendering it competent to usecheap drawn tubes for this purpose. After the chamber is charged withair the apparatus is in working condition, and ready for attachment toany hydraulic machine, wherever it is desirable to accumulate, store up,and give out hydraulic force.

The attachment is made by ordinary tube to aperture 0, and an excess ofpressure fills the chamber 1) and forces against the lower end of piston42, and whenever the pressure is slightly in excess of the air-pressurewithin chamber h the piston will rise, making room for the storage offluid-pressure, which is expelled and fed to the hydraulic machinewhenever there is a demand for the same,

made evident by release of pressure in chamber b. The piston a floatsbetween the two extremes of pressure, and makes a movable wall betweenthe fluid and gas pressures, that prevents absorption of the gas by thefluid, and prevents the escape of gas on the release of thefluid-pressure.

The piston on the extreme upper stroke meets an obstruction in screw i,which limits its motion, and any further forcing of fluid is preventedfrom bursting tube g by the escapevalve in piston n, which in that casepermits the fluid to flow through the piston until chamber h be filledwith the maximum pressure,

The said valve in piston 02 is provided with an ordinary spiral spring,that presses upon the valve, preventing its opening on all occasionsexcept in the emergency described, and for which it is provided as ameasure of safety against the bursting of tube g.

The tube f and cock 1 enable the drawing off of any accnm ulated fluidin the base of chamber h.

What I claim, and desire to secure by Letters Patent, is-

1. The combination of the receptacle h, internal light-metal tube, g,communicating with the receptacle 71. at the upper end, and the pistonn, sliding in the tube g, and provided with an inlet-valve,substantially as set forth.

2. The combination of the tube 9, its outletopenings and piston, andself -acting inlet valve, constructed and arranged to permit the fluidto pass through the piston when the pressure below is excessive, andwhen the mo tion of the piston is arrested.

3. The combination of the tubes 9 h, heads (I m, bolts 70 7c, slidingpiston n, and pillar a, supporting the whole, substantially as setforth.

4. The combination, with the cylinders g h and piston n, of the tube fand cock 1, substantially as specified.

5. The chamber 1), in combination With the chamber h, stationary tube g,and piston n, sliding in said tube 9, substantially as set forth.

THOMAS SHAW. Witnesses:

ELIAS J. SHAW, '1. J. RICHARDS.

